• Korean Journal of Construction Engineering and Management
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• v.9 no.4
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• pp.182-192
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• 2008

The purpose of this research is to identify problems and solutions of domestic Life Cycle Cost analysis in BTL(Build-Transfer-Lease), a PFI(Private Finance Initiatives) project. It is expected BTL would be quite effective delivery method for public construction introducing the private's major capital investments and technologies, and obviously LCC analysis is becoming more important factor for success of BTL projects. Nevertheless, there are still some complicated issues in LCC analysis, a technique for selecting the optimal VE(Value Engineering) proposals and estimating OM&R (Operation, Maintenance, & Repair) cost of the buildings, and has been applied limitedly. This research mainly focuses on educational facility, as most frequently delivered by BTL currently, especially with two levels (Alternative LCC and Building LCC) , which is occupied main potion in BTL project. In addition, it identifies four main problems and suggests their solutions through case studies focusing six major factors (WBS, Repair Information, Life Cycle, Time value of money, Repair Information Database, LCC Model) from three projects. Advanced development of this research requires closer partnership between the private / public sectors, and their long term strategies.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.977-982
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• 2007

There have been many efforts in automatic object recognition using computing technologies. Especially in the development of automated construction equipment, automatic object recognition is very important issue for the proper equipment maneuvering. 3D laser scanning, which uses (time-of-flight) method to construct the 3-dimensional information, is applied to the civil earth work environment for its high accuracy, quick data collection, and object recognition capability that will be developed by the authors in the future. The 3D earth model is also used as a fundamental information for intelligent earth work task planning. This paper presents the analysis of the 3D laser scanner market and selection of the most optimum 3D scanner for the intelligent earth work planning. As well as the hardware configuration for the automated 3D earth modeling is developed but also the software structure and detailed user interface are designed in this research. In addition, it is presented in this paper that the accuracy comparison test between TotalStation(R) which is a traditional survey tool and ScanStation(R). The accuracy test is done by relative distance measurement using known targets.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.892-898
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• 2007

This study aims to implement an efficient process management system for small and medium sized(local) construction companies and a performance management system for the Korean construction industry. The process management system by Lean Construction is Web 2.0 platform-based and creates clusters with numerous general contractors and sub-contractors, which will enable mutually organic process management. Plus, this system will enable them to compare project performance management by analyzing it during or after a project by collecting and accumulating lots of data occurring in pursuit of a project. These performance management cases will be of help in process planning during similar upcoming projects. This study is expected to somewhat reduce the burden of implementing a complicated process management protocol and system that Korean small and medium sized (local) construction companies experience with their web-based process management, and is supposed to realize accurate performance management with highly reliable data which are significantly accumulated within the database.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.4
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• pp.321-327
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• 2017

In this study, to investigate the shape of the back bead as a weld quality parameter and to select the optimal condition of the root-pass TIG welding of a horizontal butt-joint, an experimental design and the response surface method (RSM) have been employed. Three parameters are used as input variables, which include the base current, peak current, and welding speed. The back bead width is selected as an output variable representing the weld quality, the target value of the width is 5.4 mm. Conducting the experiments according to the Box-Behnken experimental design, a $2^{nd}$ regression model for the back bead width was made, and the validation of the model was confirmed by using the F-test. The desirability function was designed through the nominal-the-best formula for the appropriate back bead width. Finally, the following optimal condition for welding was selected using the RSM: base current of 0.9204, peak current of 0.8676, and welding speed of 0.3776 in coded values. For verification, a test welding process under the optimal condition was executed and the result showed the back bead width of 5.38 mm that matched the target value well.

• Journal of the Korean association of regional geographers
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• v.15 no.5
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• pp.525-536
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• 2009

In the period of rapid economic growth, it is possible to practice the growth policy by factors input and the regional development policy by the dispersion of growth. But, in the period of weakened growth, this model loses its theoretical and practical merit. The endogenous regional development model that can efficiently cope with a international competition and a uncertainty of international economy become an alternative policy of growth and regional development. France, which had a problem of overcrowding in the capital region by the centralized growth policy and regional development policy, phase the regional innovation system policy in order to establish the foundation of an endogenous regional development from the 1970's. The regional innovation system policy in France which pursues simultaneously the systematic regional knowledge creation and the regional development is very suggestive to the regional innovation system policy in Korea that pursues the endogenous regional development and the solution of the regional disparity.

• The Journal of Engineering Geology
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• v.12 no.2
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• pp.179-188
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• 2002

With improving computer penormance and advancing simulation techniques, a growing number of softwares are being developed for visualization of investigation results in geotechnical problems. It is a very important subject for geological site investigation to understand or predict if there would be any hazardous geological conclition that might cause any increase of construction costs or an extension of construction period. A 3-D (three-climensional) visualization technique may be one of the powerful tools to overcome an uncertainty problem of geologica] site investigatior. The paper describes an overview of a newly developed geotechnical 3-D interpretation system for the purpose of applying the 3-D visualization technique, GIS (geographic information system) and D/B (database) to tunnel design and construction. VR (virtual reality) and 3-D visualization techniques are applied in order to develope the 3-D model of characteristics and structures of rock mass. D/B system for all the materials related to site investigation and tunnel construction is developed using GIS technique. This system is very useful for civil engineers to make a plan of tunnel construction at the design stage and also during construction with the advantage of improving the economy and safety of tunnels.

• Journal of Environmental Impact Assessment
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• v.28 no.6
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• pp.616-625
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• 2019

Health impact assessment is implemented within the Environmental impact assessment for the purpose of minimizing health damage by predicting the impact on human health following implementation of the development project. In health impact assessment, manual revision is required due to the lack of consistency in the method of estimating hazardous air pollutants emissions. This study estimated the emissions by calculating the emissions of hazardous air pollutants based on the actual industrial complex development cases and completed health impact assessments. As a result of risk assessment based on exposure concentration using CALPUFF model, the risk assessment results were different for each of the emission estimation methods, and manual improvement on the emission estimation method is needed.

• Microbiology and Biotechnology Letters
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• v.42 no.2
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• pp.202-206
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• 2014

A response surface method based on a central composite design experiment was used to determine the optimum conditions for pretreatment of persimmon peel. It was mathematically predicted that the maximum amount of reducing sugars would be obtained at an $H_2SO_4$ concentration of 1.77% (w/v) and a heat treatment time of 26.4 min. A reducing sugar concentration of 63.23 g/l was obtained under the optimum pretreatment conditions determined by RSM. Under anaerobic growth conditions, Saccharomyces cerevisiae NK28 produced 15.52 g/l of ethanol with a yield of 0.34 g ethanol/g glucose from pretreated persimmon peel, which corresponded to 14% and 26% enhancements in ethanol productivity and ethanol yield, respectively, compared with those obtained in aerobic growth conditions. This study suggests that persimmon peel might be a useful substrate for bioethanol production by yeast fermentation.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.3
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• pp.223-231
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• 2009

This study intends to develop a GIS-based environmental assesment technique for environmental friendly road route plan using a spatial analysis function. After embodying an impact range based on the analysis of factors which cause the environmental damage by the road construction, a literature survey on a diverse grading cases and legal regulations was conducted. As a quantitative model for the spatial analysis, AHP was selected. As the environmental assessment, 8 items such as topography & geology, animals & plants, soil ecology, water quality, air quality, noise, land use, and landscape were selected. and then finally classified into three-grades using a pairwise comparison of the alate collected by a questionnaire surveying, weighting values were applied to there 8 items. The highest weight value, the grade 1 among eight was 0.191 for animals & plants. As the result of verifying the above method for the case region, the most environment-friendly road route could be generated.

• Journal of Korean Society of Environmental Engineers
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• v.39 no.2
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• pp.66-73
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• 2017

This study was to evaluate the influential parameters such as intial Cs concentration, reaction temperature, contact time and pH variation of solution on Cs adsorption. Using the experimental data, adsorption kinetics, isotherms and thermodynamic properties were analyzed. The Cs ion adsorption of the zeolite X was effective in the range from pH 5 to 10 and reached equilibrium after 60 minutes. The adsorption kinetics and isotherms of Cs ion with the zeolite X was described well by the pseudo-second-order kinetic and Langmuir isotherm model. The maximum adsorption capacities of Cs ion calculated from Langmuir isotherm model at 293~333 K were from 303.03 mg/g to 333.33 mg/g. It was found that thermodynamic property of Cs ion absorption on the zeolite X was spontaneous and endothermic reaction. The experimental data were fitted a second-order polynomial equation by the multiple regression analysis. The values of the dependent variable calculated by this best fitted model equation were in very good agreement with the experimentally obtained values.